* Tunisia govt, opposition deadlocked over transition
* Recent turmoil sparked by murder of opposition leader
* Islamist-led gov't faces more protests Saturday
Tunisia's powerful labour movement on Friday urged the country's Islamist-led government to make "painful" concessions to end a stalemate over its rule after talks with secular opposition failed to break the deadlock.
Two and half years after the overthrow of its autocratic leader triggered the wave of "Arab Spring" rebellions, Tunisia's crisis is threatening transition in a country once seen as the region's promising model for fledgling democracy.
Tunisia has been caught up in turmoil since late July after the second assassination of an opposition politician by suspected Islamist militants triggered mass protests and demands that the government step down.
The Tunisian General Labour Union or UGTT, a nation-wide federation using its heft to push parties to a compromise, has proposed the government step aside for a caretaker cabinet to hold new polls.
But ruling Islamist Ennahda party that heads the coalition government and a broad array of secular parties opposing it have failed to reach agreement on transition, prompting the opposition to declare the talks dead this week.
"There is a new proposal for the opposition and the coalition to get out of this crisis," Hussein Abassi, leader of the UGTT, told reporters. "The coalition has to make some painful concessions for the good of the country."
He gave no details. But Abd Essater Ben Moussa, president of a human rights organisation also brokering negotiations, told Reuters the proposal would have a strict timeline and talks could restart next week.
Accusing the government of stalling on transition, Tunisia's opposition plans more protests on Saturday as part of its campaign for Ennahda to step aside.
Ennahda and its two small secular coalition partners have said they would only be ready to step down after a month and has said it wanted time for a commission to finish work on drafting a new constitution.
The opposition coalition, called the Salvation Front, banded together after the murder of prominent opposition politician Mohamed Brahmi in July, six months after another leftist leader was gunned down.
Opposition mass protests and the decision by an assembly writing the new constitution to suspend its work have thrown the country into its worst crisis since autocratic President Zine al-Abidine Ben Ali was ousted in January 2011.
The turmoil has pushed Tunisia, whose current government was only meant to run affairs during a one-year transition, away from its roadmap for the new constitution and a caretaker cabinet to oversee voting for a fully democratic parliament.